Smoking is the leading preventable cause of death in the U.S., contributing to more than 400,000 deaths annually. Smoking cessation, even at older ages, reduces major health risks and increases longevity and the quality of life. The analysis of smoking cessation by people who reached age 55 in four different decades will improve our understanding of the determinants of cessation by older smokers and the potential for public policies to influence these decisions. The first specific aim of the project is to develop a new database from existing data by combining three well-known secondary longitudinal data sets - two of the samples of the National Longitudinal Surveys (NLS) Original Cohorts, and the Panel Study of Income Dynamics (PSID) - to create a merged sample for analysis. To accomplish this specific aim, we will develop methods to re-compute sampling weights that reflect differences in sample design, response rate, and attrition across the data sets. The resulting merged sample will allow for a rich empirical model and will provide more statistical power to detect important determinants of smoking cessation rates among older individuals. The second specific aim is to use the merged sample to estimate discrete time hazard models of the probability that an older smoker quits. Retrospective questions on smoking in the NLS and PSID will allow us to construct lifetime smoking histories. Using the smoking histories, we will examine the determinants of smoking cessation from the 1960s to the 1990s. Using information on geographic location, the project will merge policy variables with the core data to provide histories of the policy environments faced by respondents. These data allow us to study how quit rates are influences by taxes, direct restrictions on smoking, information about the health consequences of smoking, and the availability and advertising of smoking cessation products.